For example, in endoscopic surgery (also referred to as “laparoscopic surgery”), a plurality of holes are drilled on an abdomen of a patient, after a trocar (cylindrical instrument) is inserted as a passage port of an instrument, a tip of forceps having a shaft is inserted into a body cavity through the trocar, and surgery for the affected part is carried out. Grippers, scissors, and blades of an electrosurgical knife for gripping biological tissues are mounted to the tip of the forceps as a working unit.
As the forceps that are inserted from the trocar, in addition to general forceps that does not have a joint at the working unit of the tip, forceps that have a plurality of joints at the working unit, which are known as a manipulator or manipulator system have been developed. An example is disclosed in Japanese Application Publication No. 2004-105451. The manipulator allows the operation to be performed with a relatively high degree of freedom in the body cavity and the manipulation is relatively easy.
The manipulator has a working unit that includes a tip operating unit (also referred to as an “end effector”) provided at the tip of the slender shaft, and an actuator that drives the tip operating unit through a wire is provided at a main body portion (operating unit). The wire is wound around a pulley at a base end side of the main body portion (or operating unit).
In the above-disclosed manipulator, a plurality of joint portions are provided at a tip operating unit, and the tip operating unit can perform a roll-axis operation of carrying out a rotation operation about an axial direction of the tip operating unit, a yaw-axis operation and a pitch-axis operation of carrying out a swing (yawing) operation along a direction that intersects the axial direction based on the drive of the actuator. Relatively high operability can thus be achieved in a body cavity.
However, it is considered that individual differences in the operating speed of the easy to handle tip operating unit are generated according to doctors handling the manipulator and an optimal operating speed may be also different according to a surgical form or a kind of the tip operating unit (for example, gripper, scissors).